When BMW began to integrate a service indicator (SI) back in the 1990's, computers and DME systems were very expensive, inefficient and everyone was scared of them. Some mechanics got themselves into a lot of trouble initially the service indicator didn't just reset itself after an oil change. That was something only a trained BMW technician could do. The well equipped mechanic impressed his BMW customers with a $4,000 laptop, running Windows 3.1 and a copy of Carsoft (Now called iCarsoft) that could display live data, read out fault codes and also reset the SI and clock symbol.

It didn't take long and some unscrupulous DIY enthusiasts figured out how the magic works and gave the trick away, resulting in aftermarket 'BMW SI reset units' that simply plug into the DLC socket under the bonnet. The rest was pretty basic, just a button that the user would press for a number of seconds...and that's it!

A reset unit can be purchased from Ebay and costs less than a tyre valve cap from BMW. It is undoubtedly the safest method of resetting the SI and brake fluid clock symbol. However, considering the simplicity and the certainty that I will not find my reset tool when I need it, I prefer the easier method described below. I have serviced my wife's E36 Z3 for the past 20 years and the method still works every time.